Treating filter fibers



Patented Mar. 29, 1938 TREATING FILTER FIBERS Robert C. Williams, Columbus, Ohio, assignor to The Ironsides Company, Columbus, Ohio, a

corporation of Ohio No Drawing.

Application July I, 1936,

Serial No. 89,482 2 Claims. 101. 183-45) This invention relates to an improved composition, composed primarily of petroleum hydrocarbons and deliquescent salts, especially adapted for the purpose of treating hemp and other 5 cellulosic or vegetable fibers in order to render the latter, when in the form of a loose assemblage, more efiicient when employed in air filtration capacities.

Hemp fibers are being used to a limited extent ,0 as air filters in conditioning apparatus for removing dust or solid particles from air or other gaseous fluids and also for thermal insulation purposes. The same, however, are of vegetable origin and do not possess the inflammable properties of rock, glass or other siliceous wools. I have found that such hemp fibers, however, when sprayed with a substantial percentage of a combination of petroleum hydrocarbons, calcium chloride, bentonite and water preseng coated surfaces of the above combination of materials in a form which effectively retains dust, or other solid particulate impurities occurring in the air and which contact with such surfac'es. Furthermore, dust which adheres to these coated fibers acts as a wick, becoming permeated with the composition and thereby enabling the latter to retain additional dust.

An important advantage of this novel treating composition is that the ratio of petroleum oil to deliquescent salt can be established, so that under various atmospheric conditions, sufficient fireproofing effect can be obtained whereby the hemp fibers, which of themselves bum readily, when coated with said composition do not support combustion on being subjected momentarily,

or for a short period, to a flame.

An example of my preferred'formula in percentages by weight is as follows:

Per cent slight pressure, is preferably employed to handle the product without dilution with water, as the texture thereof is short. Dilution with water, prior to spraying, if it is desirable, can be accomplished by merely stirring the water into the emulsion.

In the case of an air filter composed of a loose assemblage of hemp fibers coated with a composition of the above formula, adapted for use in air conditioning equipment in which the air passing through the filter is not refrigerated and consistently has a high relative humidity, it is possible that a lower percentage of deliquescent salt would be preferable. In other words, a lower ratio of the calcium chloride to the petroleum hydrocarbon under such conditions would check excessive moisture absorption, which may be un-'- desirable because of possible excess dripp e. The formula given above, however, contains sumcient calcium chloride to serve quite effectively under conditions of relatively low humidity, and also affords a substantial measure of fire resistance under such conditions.

The low cost of such treating material is .very

advantageous and when the filter becomes charged with dust so that the resistance tothe passage of air is too great, the entire filter is discarded without involving any considerable economic loss.

The bentonite serves to satisfactorily emulsify the oil in the water and being inexpensive is quite desirable in this connection.

Other emulsifying agents not adversely affected by the high concentration of deliquescent satisfactorily. It is believe salt will also serve d preferable to mix the ingredients in the following order, namely, water, bentonite, deliquescent salt and oil.

Examples of other formulas which may be successfully employed are as follows:

Light paraflin oil (vis. 100 sec. Saybolt at 100 F.) 22.0

Neutral degras 1.1

Per centv Water--. 37.5

Bentonite 1.9

Calcium chloride 37.5 Technical white oil (vis. 100 sec. Saybolt at 100 F.) 23.1

v In the latter formula, a paraflin oil having a viscosity of approximately sec. Saybolt at d. has also been found satisfactory. However,

the formulas having the tec been more satisfactory from elimination of odor.

hnical white oil have the standpoint of the No fire hazards of any kind exist during the to collect solid particulate impurities occurrins in applicatlonolthe emulsion tothehempflbers and air passed through the fibers and to preclude appreciable protectionlsextcnded the nberswhen combustion when momentarily subjected to a coetedwiththecompodtiomabovesettorth. flame.

5 Whatisclaimedis: L'Iheartieleassetforthinclaimlinwhich 5 1. As anew articleol' manufacture, an In alter the fibe s are e p. t deliquesc a 18 c vegetnble fibers canted with 3 mm clilm chloride, and. the oil is technical white 011 deposited from an emulsion of hydrocarbon oilhaving a viscosity 0! 1 on 8 711 in-Inter containing a. dt salt and ben- 1 1". 7

l0 tonite; the film so deposited being in an amount ROBERT C. WILLIAM l0 

